Strip winding apparatus



July 30, 1963 c. ALLEN, JR., ETAL 3,099,190

STRIP WINDING APPARATUS Filed Feb. 1, 1961 2 Sheets-Sheet 1 anmwmm "PM I5/ 1 g /2 k ENTORS. Chester Allen, Jr. 71. 2. BY Freer! Ber/ 100 Andrus#Jfirlp July 30, 1963 c. ALLEN, JR.. ETAL 3,

STRIP WINDING APPARATUS Filed Feb. 1, 1961 2 Sheets-Sheet 2 INVENTORS yFreer flndrus stwrl Dilibrnegs United States Patent 3,0921% STRIPWKNDENG APPARATUS Chester Allen, .lr., and Freerlr Berldoo, Milwaukee,Wis, assignors to A. 0. Smith Eerporation, Milwaukee, Wis, a corporationof New York Filed Feb. 1, i961, Ser. No. 86,426 3 Claims. (Cl. 93-80)This invention relates to strip winding apparatus and is particularlydirected to apparatus for spirally winding upon a tubular form awoofless strip or Web of resin having longitudinally extendingreinforcing fibers to provide a protective cover or a tubular pipe-likemember.

Apparatus for wrapping a strip or web of material upon a tubular formmay include an annular reel containing a coil of the wrapping web withthe tubular form moving coaxially through the reel. The web is withdrawnfrom the reel over suitable spiral directing or twisting rollermechanism and spirally wrapped around the tubular form by simultaneousrotation of the reel and coaxial movement of the tubular form. Forexample, a pipe wrapping machine generally of this variety is shown inPatent 2,011,172 to I. Coleman et al.

Recent attempts have been made to form self-support ing plastic pipe andthe like by similarly spirally wrap ping of a resin impregnated fibrousstrip upon a mandrel or form and after curing or setting of the resin,the wrapping is removed to provide a self-supporting tubular member. Inthe formation of such products, an appreciable twist is imparted to theweb during the wrapping operation to establish the desired angular orspiral winding of the web. When the web is woofless, the strength andcohesion transversely of the web are practically nonexistent. As aresult, appreciable splitting and roping as well as resin flakingresults during the winding process.

The twisting of the web further results in uneven lateral distributionof the tension in the web which may move across the roller mechanism andresult in an uneven overlap of the adjacent spirals in the finalproduct. A fixed roll can be employed to eliminate this movement.However, resin deposits tend to build up upon the fixed roller andresult in splitting of the tape adjacent the built-up portions.

The present invention provides a guide assembly between the reel and thetubular form or mandrel for imparting a twist to the tape or web Withoutthe disadvantages of the prior art structures. The structure of thepresent invention permits relatively large wrapping or winding angleswithout the splitting or roping and maintains an even distribution ofthe tension across the web to an extent which allows rapid and highlysatisfactory wrapping.

in accordance with the present invention, a rotating distribution reelor cylinder is provided with the mandrel relatively moved longitudinallyor axially through the center of the reel. A series of circumferentiallyspaced guide rollers are interposed between the take-off from therotating distributon reel and the tubular form. The guide rollers arearranged to progressively increase the twist until at the discharge tothe pipe the desired winding angle is established. Each of the rollersimparts a very slight twist and thus establishes the final desiredwinding angle in slow incremental changes.

To obtain the advantages of the present invention, the adjacent rollersare mounted such that a plane defined by the axis of each roller and thetan gency line formed where the web leaves the roller is parallel to theplane defined by the axis of the next adjacent roller and the tangencyline formed where the strip first engages such adjacent roller. Thisparallel plane arrangement results in the rollers functioning tomaintain even distribution of the tension across the width of the stripand insures winding of the tape upon the tubular form without splitting,roping or resin breaking.

The present invention thus provides a new and novel guide for stripwinding apparatus which is particularly adapted for winding of wooilessweb or strips of resin impregnated unidirectional fibers onto a suitabletubular member or form.

The drawings furnished herewith illustrate the best mode presentlycontemplated for carrying out the invention.

In the drawings:

FIG. 1 is a side elevational view of a pipe forming apparatusincorporating a web twisting cage constructed in accordance with thepresent invention;

FIG. 2 is an enlarged perspective view of the winding apparatus shown inFIG. 1;

FIG. 3 is a perspective view of a tubular member formed with theapparatus shown in FIG. 1;

FIG. 4 is an enlarged view of a winding cage constructed in accordancewith the invention and shown in FIGS. 1 and 2;

FIG. 5 is a view taken on transverse plane 5-5 in FIG. 4;

FIG. 6 is an enlarged view of a pair of rollers incorporated in thewinding cage 3 and illustrating the relative position maintained betweensuccessive adjacent rollers;

FIG. 7 is a diagrammatic illustration of the relative angular positionof the first and second cage rollers; and

FIG. 8 is a top view of the second cage roller shown in FIG. 7.

Referring to the drawings and particularly to FIGS. 1 and 2, theillustrated embodiment of the invention generally includes a rotatabledistribution reel or drum 1 within which a coil of web 2 is secured. Awinding mandrel 3 is movably mounted coaxially within the drum 1 toreceive the Web 2 as drum 1 rotates and the mandrel 3 is moved axially.A winding guide 4 forming a part of the present invention is interposedbetween the takeoff from the drum 1 and the mandrel 3 and serves toproperly :guide web 2 and impart in selected twist to the Web 2 as theweb 2 moves from the drum 1 to the mandrel 3 to establish a desired orselected angle of winding.

The drum 1 is rotated and the mandrel 3 simultaneously moved axiallythrough the drum to continuously Wind Web 2 upon the mandrel 3 with theadjacent spirals overlapping slightly.

The present invention is particularly directed to winding of a web 2which consists of resin impregnated unidirectional fiberglass or thelike. The web 2 is then a woolless strip having a lateral strength orcohesion which is practically non-existent. The web 2 is of anyconvenient width which is adapted to be superimposed upon the mandrel 3.After the resin is cured or set, a self-supporting tubular member 5formed of plastic and reinforced by glass fibers results, as shown inFIG. 3.

The illustrated drum 1 includes an outer cylindrical shell 6 and a pairof axially spaced radial sidewalls 7 which project partially inwardlyfrom the outer cylindrical shell 6 to lorm an inwardly opening annularshaped drum. A series of circumferentially spaced rollers 8 are disposedbetween the sidewalls at the inner periphery of the sidewalls to formand constitute a cylindrical winding form upon which the coil of web '2is Wound. The rollers 8 are parallel to the axis of the drum 1 and themandrel 3 to allow removal of the tape over one of the rollers 3 Withoutany twist or angular displacement of the tape. Each of the rollers 8includes an inner core or mounting rod 9 which is secured at oppositeends to the sidewalls '7 in any suitable manner. A sleeve 10 is mountedupon each of the rods 9 for free rotation to minimize frictional 3forces established as the tape is withdrawn from the coil of web 2.

An opening or window 11 is formed in the cylindrical shell 6 to permitinitial winding of the web upon the rollers 8 Three circumferentiallydistributed mounted brackets 12 are welded to the outer side of thecylindrical drum shell 6 and secured to a fly wheel 13 to rotatablymount the drum 1. A drive hub 14 is formed on the back side of fly wheel13 and connected by a suitable chain 15 to a motor 16. The motor 16 isany suitable variety adapted to establish a constant rotational speed ofthe drum 1 to maintain a constant withdrawal of the web 2 from the drum1 to the mandrel 3.

The mandrel 3 is a tubular core supported in opposite ends in similarbearing units 17. A drive wheel 18 is mounted in driving relation to thetrailing portion of the mandrel 3. A constant speed motor 19 is coupledto the drive wheel 18 to continuously drive the wheel at a preselectedconstant speed. The mandrel 3 is therefore moved axially through thedrum 1 at a constant speed for progressive spiral winding of the tapeupon the mandrel.

In accordance with the illustrated embodiment of the invention, theguide 4 is constructed as follows.

Referring particularly to FIGS. 1, 2, 4 and 5, a series of rollers 20are circumferentially spaced about the mandrel 3 between an initialtake-off roller 21 and a discharge roller 32. The rollers 20-22 aresecured between a pair of axially-spaced and semi-circular mountingplates 23 and extend through the drum 1. Mounting bolt assemblies 24secure the mounting plate 23 to the opposite sidewalls 7 of the drum 1to properly position the rollers 20-22 within the drum 1. Auxiliarystabilizing bolt units 25 are shown extending through and joining theupper ends of the plate 23 to provide a stable assembly. Recesses 26 inthe plate 23 accommodate mandrel 3.

The rollers 20-22 are similar to rollers 8 and each includes a corejournal 27 and a sleeve 28 freely rotatable thereon, as most clearlyshown in FIG. 4.

In accordance with the present invention, the initial take-oft roller 21is mounted exactly parallel to the drum roller 8 over which the web 2 iswithdrawn from the drum 1. The adjacent intermediate roller 20 iscircumferentially spaced from roller 21 and mounted at a diagonal withrespect to the first roller to impart a slight twist to the tape 2 as itmoves from roller 21 over the adjacent roller 20. The relationshipbetween the mounting of the rollers is crucial and the construction inaccordance with the present invention is most clearly illustrated inFIGS. 6-8.

Referring to FIG. 6, a radial plane 29 through roller 21 and a radialplane 30 through the immediately adjacent roller 20 are parallel to eachother with the rollers 20-22 properly aligned and mounted. Radial plane29 is formed by and includes the axis 31 of the initial roller 21 andthe tape tangency line 32 formed at the line that the web 2 leaves theroller 21. The plane 30 is formed by and includes the axis 33 of theimmediately adjacent roller 20 and the tangency line 34 at the line thatthe web 2 initially engages such adjacent roller 20. The presentinvention states that these two planes must be substantially parallel.

Referring to FIG. 7, the first roller 21 and the adjacent roller 20 areshown as viewed from the line of the tape 2. The pivot point 35 of thesecond roller 20 is at the midpoint of the two rollers 20 and 21 andthus at the midpoint of the width of tape 2. This relationship ismaintained for all subsequent displacement of the rollers 20.

Referring to FIG. 8, atop elevational View of the roller 20 shown inFIG. 7 is illustrated. The true tangency line is shown at 36. In actualpractice, the angular displacement of the next succeeding roller 20tends to lift one edge and lower the opposite edge of the tape 2 andactually shifts the tangency line such as typically shown at 37.Generally, unless exceptionally large twist 1S 1mparted between adjacentrollers, the displacement does not appreciably or practically effect theoperation and functioning of the invention and the tangency line 36 canbe employed in designing the apparatus.

The successive and adjacent rollers in the series of rollers :20-22 arearranged in like relation to each other. The successive rollers 20 and22 are thus diagonally offset with respect to the previous roller toincrease the winding angle and to thereby impart a preselected twist tothe web 2. Each pair of rollers preferably provides a relatively equalangular displacement or twist in the web 2 although in actual practice arelatively complicated roller system is required therefor.

The number of rollers 20 which is employed is determined by thepermissible or desirable stress which can be tolerated in web 2.

The operation of the illustrated embodiment of the present invention issummarized as follows.

The tape 2 is wound upon the rollers 8 within the drum 1 to form a coil.The mandrel 3 and the guide 4 are concentrically assembled within thedrum 1 as previously described. The inner end of web 2 is threaded fromthe drum 1 back over the take-off roller 8 and then uponthe outside ofthe rollers 20-22 and the free end is secured to the mandrel 3. Themotors 16 and 19 are simultaneously energized to provide synchronousmovement between the rotation of the drum 1 and the longitudinalmovement of the mandrel 3 through the drum 1. The movements arecorrelated such that the spiral wrapping about the mandrel 3 establishesa tubular member 5 having overlapping portions between the immediatelyadjacent spirals.

The rollers 20-22 serve to conduct and change the direction of the tapeas it moves from the drum 1 to the mandrel 3. Each adjacent pair in theseries of rollers 20-22 imparts a substantially equal twist to alltransverse sections of the tape and thus maintains a constant widththroughout the length of the laterally unsupported tape. This eliminatesforces tending to move the tape axially of the rollers 20-22.

The illustrated embodiment of the invention includes the guide assemblysupported within the tape supply. The assembly can also be mountedexteriorly of the tape supply which is then unwound from the outercircumference. The latter construction permits a larger supply of tapeand thus requires less frequent shut-down of the winding apparatus forreplacement of the tape. A11 exteriorly mounted assembly is howeversomewhat larger in size.

The present invention thus provides an improved strip w nding apparatuswhich is particularly suited for spiral winding of a woofless strip orweb at any desired wrapping angle.

Various modes of carrying out the invention are contemplated as beingwithin the scope of the following claims particularly pointing out anddistinctly claiming the subject matter which is regarded as theinvention.

We claim:

1. An apparatus for winding a woofless web of unidirectional fibersimpregnated with a resin in a spiral pattern to form a tubular member,comprising, a mandrel, cylindrical support means for supporting the webin coiled form, and a series of guide members separate from said supportmeans and circumferentially distributed about the mandrel and serving toguide the web from said support means onto the mandrel, the first ofsaid guide members having its axis parallel to the mandrel andsuccessive guide members from said first guide member being tilted aboutthe central incoming tangency point to impart a progressive twist in thesame general direction to the web, and said guide members being arrangedwith the plane defined by the axis of each guide member and the tangencyline formed at the discharge line of the guide member beingsubstantially parallel to the plane defined by the axis of the nextadjacent roller and the tangency 5 line formed where the Web engagessuch adjacent guide member.

2. An apparatus for winding a woofless web of unidirectional fibersimpregnated with a resin in a spiral pattern to form a tubular member,comprising, a mandrel, a generally cylindrical support member to supportthe web in coiled form, and a series of cylindrical guide rollerscircumferentially distributed about the mandrel and serving to guide theweb from the support member onto the mandrel, said series of rollersincluding a first roller to receive the web from the support member andincluding a last roller to discharge the web onto the mandrel, saidseries of rollers also including a plurality of intermediate rollerslocated between the first and last rollers, said first roller having itsaxis parallel to the axis of the mandrel and said intermediate rollersand said last roller being tilted about the central incoming Webtangency point to impart a twist to the web, and said rollers beingarranged With the plane defined by the axis of each roller and thetangency line formed at the discharge line of the roller beingsubstantially parallel to the plane defined by the axis of the nextadjacent roller and the tangency line formed where the web engages suchadjacent roller.

3. An apparatus for winding a woofless web of unidirectional fibersimpregnated with a resin in a spiral pattern to form a tubular member,comprising, a mandrel, a winding head including a generally cylindricalsupport member to support the web in coiled form with said supportmember being mounted coaxially of said mandrel, means for rotating saidhead, a series of guide rollers mounted on the head andcircumferentially distributed about the mandrel, said series of rollersincluding a first roller to receive the web from the support member andincluding a last roller to discharge the web onto the mandrel, saidseries of rollers also including a plurality of intermediate rollerslocated between the first and last rollers, said first roller having itsaxis parallel to the axis of the mandrel and said intermediate rollersand last roller being tilted about a central incoming web tangency pointto impart a progressive twist to the web in the same general direction,and said rollers being arranged with the plane defined by the axis ofeach roller and the tangency line formed at the discharge line of theroller being substantially parallel to the plane defined by the axis ofthe next adjacent roller and the tangency line formed Where the webengages such adjacent roller.

References Cited in the file of this patent UNITED STATES PATENTS986,690 Clank Mar. 14, 1911 2,001,546 Pourtier May 14, 1935 2,011,172Coleman et al Aug. 13, 1935 2,910,822 Bunch Nov. 3, 1959

1. AN APPARATUS FOR WINDING A WOOFLESS WEB OF UNIDIRECTIONAL FIBERSIMPREGNATED WITH A RESIN IN A SPIRAL PATTERN TO FORM A TUBULAR MEMBER,COMPRISING, A MANDREL CYLINDRICAL SUPPORT MEANS FOR SUPPORTING THE WEBIN COILED FORM, AND A SERIES OF GUIDE MEMBERS SEPARATE FROM SAID SUPPORTMEANS AND CIRCUMFERENTIALLY DISTRIBUTED ABOUT THE MANDREL AND SERVING TOGUIDE THE WEB FROM SAID SUPPORT MEANS ONTO THE MANDREL, THE FIRST OFSAID GUIDE MEMBERS HAVING ITS AXIS PARALLEL TO THE MANDREL ANDSUCCESSIVE GUIDE MEMBERS FROM SAID FIRST GUIDE MEMBER BEING TILTED ABOUTTHE CENTRAL INCOMING TANGENCY POINT TO IMPART A PROGRESSIVE TWIST IN THESAME GENERAL DIRECTION TO THE WEB, AND SAID GUIDE MEMBERS BEING ARRANGEDWITH THE PLANE DEFINED BY THE AXIS OF EACH GUIDE MEMBER AND THE TANGENCYLINE FORMED AT THE DISCHARGE LINE OF THE GUIDE MEMBER BEINGSUBSTANTIALLY PARALLEL TO THE PLANE DEFINED BY THE AXIS OF THE NEXTADJACENT ROLLER AND THE TANGENCY LINE FORMED WHERE THE WEB ENGAGES SUCHADJACENT GUIDE MEMBER.